1. Field of the Invention
The invention concerns a programmable LED lighting device and method.
The present invention concerns the field of lighting, in particular in aquatic environments. Advantageously, it aims at a lighting device featuring one or several submersible devices, also called underwater spotlights, usable for lighting swimming pools and their immediate surroundings (beach, terraces, gardens . . . ). It applies also to the lighting of fountains, spas or other locations, as well as to lighting in the air.
2. Description of Related Art including Information Disclosed Under 37 CFR 1.97 and 7 CFR 1.98
Immerged spotlights or underwater spotlights for lighting swimming pools are widely used today to illuminate the water of the basins and their surroundings at nightfall, in order to securitize the place and to provide an esthetic rendering. More precisely, the invention applies to spotlights utilizing the technology of light-emitting diodes known as LEDs which contain a number of LEDs of intense brightness (see for example documents EP-1.840.450, EP-1.460.333).
These underwater LED spotlights are very economical. They consume very small amounts of energy (only a few Watts) and last for a very long time (more than 10 years in daily use). LEDs are also sturdier, have a longer useful life than incandescent light bulbs or fluorescent lights and have a payoff three to four times greater than those.
Evolution of LED technology has led to the emergence of spotlights offering the possibility to generate light of different colors or lighting sequences in various colors. Most often, installations using such spotlights are configured for making changes, in a controlled way by remote control. The color mix and the variation of transition speeds offer, as a rule, a very wide choice of tints and operating modes.
However, this choice is limited by the difficulty of remotely controlling, and in a synchronized fashion, the changes of the operating mode, particularly when the installation features several spotlights as is the case, for example, in applications for lighting swimming pools.
Remote control of color changes can be done by transmitting information over radio-electric waves or over wires or also by using a power cable as transmission support (broadband over power line (BPL), see for example document FR-2.931.925. These transmission devices require that the spotlights be equipped with a receiver which proves to be complex and costly, especially for residential applications.
Various solutions exist to change the color of LEDs. The US-2002/0A 63.316 document describes, for example, a device whereby a rapid power cut to the LEDs is provoked. These systems are equipped with a detection device to detect the cut which authorizes the color change, and this, thanks to the energy generally accumulated in condensers that come with the spotlight. Such operations can only occur when a switch is activated in order to cause a rapid power cut which must be neither too short nor too long so that the energy accumulated in the spotlights is able to maintain the power supply of the detection device during the duration of the power cut. On the other hand, the color change occurs through incrementation and according to a predefined order. That is to say, for a spotlight capable of emitting ten (10) different colors, it is necessary, successively, to carry out nine (9) power cuts in order to select the last color, and to make successively ten (10) cuts to return to the previous color. The drawback of this process is that one cannot choose and obtain directly and instantly the desired color. Furthermore, each power cut is of a different length so as to be interpreted by the device as a unique and complete information, therefore the lengths of the cuts must be neither too short nor too long, making the process much too limiting because of a restricted vocabulary. In effect, a cut of too short duration could be assimilated to an unwanted signal, thus creating the possibility of desynchronizing the spotlights which happens when they do not detect the cut, and a cut of too long duration could be assimilated to a power cut because of too long response time and could lead to the extinction of the spotlights.